I'm thinking of building a 24 1TB disk NAS box, but I'm not sure what the best drive configuration is. I'm looking at using the areca ARC-1280ML-2G controller, and hanging all 24 drives off of it.
I'd like it all to be mounted as one volume, due to the type of data we're storing on it. One crazy idea we had was to configure 6 4-disk RAID 5 volumes, then do software RAID 5 over those 6 volumes. That would mean any one volume could die on us and we'd still not lose data.
I should note that this is an R&D project, we've got an upcoming application where we'll be needing tens of terabytes of storage to be fast and highly available. But for the initial R&D phase we can accept some risk.
What is the best solution to this type of configuration? With 24 1 TB disks, it's likely that more than one will fail at the same time (or within the time it takes to rebuild the volume after a first failure), so I'm having trouble finding a good solution.